1. Field of the Invention
The present invention relates to a vehicle-mounted camera that is mounted on a vehicle such as a passenger vehicle.
2. Description of the Related Art
A vehicle-mounted camera that uses a camera module mounted on a vehicle is being widely used for recording the traveling state of the vehicle or assisting the driving of the vehicle. The vehicle-mounted camera 901 shown in FIG. 68 is used as a so-called drive recorder (for instance, refer to Japanese Patent Application Laid-open No. 2000-6854). The vehicle-mounted camera 901 films the forward vehicle traveling direction with a camera module mounted on the front window or the room mirror of the vehicle 801. The video picture of the vehicle-mounted camera 901 is recorded for a predetermined length of time from several seconds to several minutes retroactively, for instance, from the time that a motor vehicle accident occurs, or recorded continuously. Meanwhile, the vehicle-mounted camera 902 shown in FIG. 68 is used as a so-called rear-view monitor (for instance, refer to Japanese Patent Application Laid-open No. 2007-62670). The vehicle-mounted camera 902 is mounted in the vicinity, for example, of the license plate (not shown) of the vehicle 801, and captures the area immediately behind the vehicle 801. The video picture of the vehicle-mounted camera 902 is displayed, for example, on a monitor that is installed in the instrument panel. The driver confirms the existence of obstacles by visually observing the video picture of the monitor upon reversing the vehicle 801.
Nevertheless, demands are increasing for the vehicle-mounted camera 901 that is used as a drive recorder to film the interior of the vehicle 801 in addition to the status of the forward direction of the vehicle 801. For example, a case requiring the filming of the interior of a vehicle would be when a passenger engages in any wrongful act within a taxi. In order to meet the foregoing demands, it was necessary to provide a separate vehicle-mounted camera for filming the interior of the vehicle in addition to the vehicle-mounted camera 901 for filming the front of the vehicle.
Moreover, the vehicle-mounted camera 902 must be installed outside the vehicle in order to capture an area that is difficult for the driver to see. Thus, the vehicle-mounted camera 902 is constantly exposed to rain and wind. Thus, sufficient waterproofing measures must be taken for the vehicle-mounted camera 902. Moreover, connected to the vehicle-mounted camera 902 is a cable (not shown) for supplying power and sending the screen images. This cable needs to be dragged from the outside of the vehicle where the vehicle-mounted camera 902 is installed to the inside of the vehicle where the monitor and battery are disposed. The laying of the cable across the outside of the vehicle and the inside of the vehicle is troublesome and not easy.
A compact camera module is widely used as means for filming, for example, the status of the inside or the outside of a passenger vehicle. FIG. 69 shows an example of a conventional camera module (for instance, refer to Japanese Patent Application Laid-open No. 2006-332288). The camera module 903 shown in FIG. 69 has an imaging element (not shown) built into the case 911, and comprises a lens 912 for forming an image in the imaging element. Moreover, the case 911 is provided with a plurality of LED modules 913. Each LED module 913 is configured, for example, by an LED chip (not shown) being built into a translucent head. As shown in FIG. 69, the plurality of LED modules 913 are disposed so that their respective main emitting directions basically coincide with the optical axis of the lens 912. According to this kind of configuration, the plurality of LED modules 913 are able to illuminate the imaging area of the camera module 903 so as to compensate for the insufficient brightness of the screen image.
Nevertheless, in order to adequately capture the state within the vehicle, a lens 912 with a relatively wide viewing angle; for example, a viewing angle of 120 degrees or more, is used. The illumination angle that the respective LED modules 913 are able to brightly illuminate is relatively narrow relative to the foregoing wide viewing angle. Thus, there were cases where the plurality of LED modules 913 would illuminate only a part of the imaging area of the camera module 903. Under the foregoing circumstances, for example, there were inconveniences in that the center portion of the captured screen image would become extremely bright and cause a phenomenon known as a so-called whiteout condition, while the peripheral portion would become dark.
Contrarily, for a camera module that is used for filming afar, a lens with a relatively narrow viewing angle; for instance, a viewing angle of approximately 10 degrees, is used in substitute for the lens 912. Here, there were cases where sufficient light would not reach the imaging area in the distance with standard LED modules, whereby filming at night or in dark places was impossible.
A relatively compact camera module is widely used as means for filming the status behind the passenger vehicle. This camera module is often installed outside of the vehicle, and is required to comprise sufficient waterproof functions (for instance, refer to Japanese Patent Application Laid-open No. 2009-107393). FIG. 70 shows an example of a conventional camera module. The camera module 904 shown in FIG. 70 has a lens unit 914 and an inner case 919 built into the case 922. The inner case 919 is mounted with an imaging element 921 via a substrate 920. The lens unit 914 is structured so that two lenses 917, 918 and a diaphragm 916 are retained with a holder 915. The lens unit 914 and the inner case 919 are mutually connected, for example, with a screw structure not shown so as to cause their mutual positions to be adjustable. The focusing of the imaging element 921 of the lens unit 914 is thereby enabled. The case 922 is of a block construction having an upper case 923 and a lower case 924. A waterproof O-ring 925 is provided between the upper case 923 and the lower case 924. The camera module 904 is thereby equipped with a certain level of waterproof function enabling it to be used by being mounted outside the vehicle.
Nevertheless, upon manufacturing the camera module 904, foremost, it is necessary to focus the lens unit 914 and the imaging element 921. This process is performed, for example, by confirming the screen image of the test pattern that is displayed by the imaging element 921 while screwing the lens unit 914 into the inner case 919. Subsequently, the focused lens unit 914 and the inner case 919 are built into the case 922. In order to properly exhibit the waterproof function of the camera module 904, the insertion of the O-ring 925 must be performed carefully. Accordingly, when manufacturing the camera module 904, it is necessary to pay attention to the focusing of the lens unit 914 and the imaging element 921, and the assembly of the case 922 with the insertion of the O-ring 925, and these two troublesome processes are required. This contributed to the deterioration in the production efficiency and aggravated the production yield of the camera module 904.
Moreover, the camera module 904 must be equipped with a cable or the like in order to supply power to the imaging element 921 and externally send the image signal received from the imaging element 921. For example, the lower case 924 is provided with a cable hole through which the cable is inserted. When using the camera module 904 by mounting it outside the vehicle, waterproofing treatment must be performed between the cable hole and the cable. As this kind of waterproofing treatment, for example, if sealing is performed using resin, it is necessary to manage the temperature of the resin material and check its application status, and the process of filling resin was not an easy process.